Ambidextrous firearm bolt

ABSTRACT

An ambidextrous firearm bolt (10) may be configured to eject from the left or right side of a firearm. The firearm bolt (10) features a firing pin (140) residing within a bolt body (120) in turn residing within a bolt carrier (110). The bolt body (120) may be inserted on either side of the bolt carrier (110) and features a selector pin (126) designed to interact with slots (112, 114) on either side of the bolt carrier (110), thereby selectively imparting a twist with respect to the firearm itself, allowing the ambidextrous ejection. A spring-loaded extractor latch (134) residing in a bolt lug (130) secures ammunition for extraction.

CROSS-REFERENCES TO RELATED APPLICATIONS

This Application claims priority as a non-provisional perfection of prior filed U.S. Application No. 62/620,941, filed Jan. 23, 2018, and incorporates the same herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to the field of firearms and more particularly relates to a firearm bolt which may be adapted to either left-sided or right-sided ejection of spend ammunition from said firearm.

BACKGROUND OF THE INVENTION

The manufacture of firearms is an old art. One of the most important advances in the art of firearms has been the advent of ammunition cartridges. Cartridge ammunition is simply a premeasured charge packed with a projectile load in a casing. A primer is also provided which ignites the charge when the primer is struck, usually by a firing pin or hammer. The projectile(s) then exit the casing through the barrel of the firearm. With the use of a cartridge, firearms may be rapidly reloaded and provide consistent results as the charge and projectile in the ammunition cartridge is uniform. However, this leaves the casing in the firearm and requires its removal. Therefore, since the advent of cartridges, there has also been a system in the firearms to eject cartridges them from the firearm—whether manually or automatically. Automatic ejection of cartridges is a necessity in automatic and semi-automatic weapons. One common ejection system is to have the firearm bolt, which positions the cartridge for firing, retract the spent cartridge and release it out a port on one side of the firearm, usually the right.

There has always been an interest in the customization of firearms. To this end many platforms have aftermarket parts available for the personalization and customization of the base weapon. One difficult customization is to switch from a right-handed ejection to a left-handed ejection as this requires not only a different bolt structure, but also that the firearm receiver be modified from the standard in order to create a left side ejection port. While some firearm platforms have receivers that do accommodate this type of customization, separate bolts need to be used for either left or right ejection. What is needed is a single bolt structure which is convertible between left and right-handed ejection, or an “ambidextrous” bolt.

The present invention is an ambidextrous firearm bolt which utilizes a central bolt head structure which may be inserted and used in either side of a bolt carrier, thereby allowing for ejection on either side of a firearm. The present invention represents a departure from the prior art in that the ambidextrous bolt of the present invention allows for the easy conversion from right to left-handed ejection in a firearm, or vice versa with the use and adaptation of a single component structure.

SUMMARY OF THE INVENTION

In view of the foregoing disadvantages inherent in the known types of firearm bolts, an improved ambidextrous bolt may provide a that meets the following objectives: that it be a single component part of the firearm, even if comprising individual sub-components, with no interchange of parts for others to make the conversion; that it be simple and easy to operate and convert, and that it be cost effective in construction. As such, a new and improved ambidextrous firearm bolt may comprise elongate bolt head with an ejector, the bolt head also designed to alternately fit in a bolt carrier in a manner to allow left and right-handed ejection of spent cartridges in order to accomplish these objectives.

The more important features of the invention have thus been outlined in order that the more detailed description that follows may be better understood and in order that the present contribution to the art may better be appreciated. Additional features of the invention will be described hereinafter and will form the subject matter of the claims that follow.

Many objects of this invention will appear from the following description and appended claims, reference being made to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for description and should not be regarded as limiting.

As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods, and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of an ambidextrous firearm bolt, in a right-handed configuration.

FIG. 2 is a top plan view of the firearm bolt of FIG. 1.

FIG. 3 is an exploded view of the firearm bolt of FIG. 1.

FIG. 4 is a partial exploded view of the firearm bolt of FIG. 1, in a left-handed configuration.

FIGS. 5A-5I are successive perspective view of the firearm bolt of FIG. 1, being converted from left-sided to right-sided use.

FIG. 6 is a perspective view of a firearm bolt and associated shotgun shell.

FIG. 7 is a partial section of the firearm bolt and shell of FIG. 6.

FIG. 8 is a side elevation of the partial cross-section of FIG. 7.

FIG. 9 is a close-up of the firearm bolt and shell of FIG. 8, taken in circle A.

FIGS. 10A-10F are successive top plan views of the firearm bolt of FIG. 1, progressing through a firing cycle.

FIGS. 11A-11F are successive front plan views of the firearm bolt of FIGS. 10A-10F.

LISTING OF REFERENCE NUMBERS IN THE DRAWINGS

-   -   10—an exemplary ambidextrous firearm bolt;     -   110—bolt carrier;     -   112—left helical slot;     -   114—right helical slot;     -   120—bolt body;     -   122—bolt head;     -   123—bolt head rim;     -   124—bolt neck;     -   125—selector holes;     -   126—selector pin;     -   128—lock pin;     -   130—bolt lugs;     -   132—extractor slot;     -   134—extractor latch;     -   136—extractor spring;     -   140—firing pin;     -   150—cartridge (shotgun shell).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference now to the drawings, a preferred embodiment of the ambidextrous firearm bolt is herein described. It should be noted that the articles “a”, “an”, and “the”, as used in this specification, include plural referents unless the content clearly dictates otherwise. It should also be noted that the illustrated firearm bolt is primarily made for a shot gun, thus the use of a shot gun shell in FIGS. 6-9. However, this is only illustrative and the use of the firearm bolt with any suitable firearm should be understood to be included within the purview of the invention. Likewise, the term “cartridge” should be read to include any self-contained ammunition unit with an explosive charge and a payload, including a shotgun shell.

With reference to FIG. 1, the firearm bolt 10 contains the firing pin 130 and comprises a carrier 110 and a bolt body 120. In FIGS. 2 and 3, it is seen that the bolt body 120 has a bulbous bolt head 122 designed to interface with a firearm cartridge and more narrow neck 124 while the carrier features two opposed helical slots 112, 114 on its dorsal side. A selector pin 126 may reside within either one of the opposed helical slots 112, 114, depending on the configuration of the bolt. The selector pin 126 is positioned in the bolt neck 124 in one of two provided selector holes 125. A lock pin 128 is utilized as a final securement pin for the whole bolt assembly, being located proximate an end of the bolt body 120 opposite the head 122. Carrier 110 may be of any general shape to comport with the firearm itself, as may bolt body 120.

In FIG. 4, the bolt head 122 features a plurality of lugs (usually, but not necessarily, three) 130, one of which has an extractor 134 residing in a slot 132. The extractor 134 is spring loaded 136 in a manner to latch on to some form of cartridge ammunition (be it a shotgun shell or rifle cartridge) when interacting with the same and then releasing it when biased against spring pressure.

As shown in FIGS. 5A-5I, the firearm bolt may be converted from left-handed to right-handed election. In FIG. 5A, the bolt 10 starts in left handed ejection and the bolt body 120 is compressed into the bolt carrier 110. The bulbous head 122 prevents the bolt body 120 passing entirely through the bolt carrier 110. The selector pin 125 is in the left helical slot 112 which is denoted with an “L”, though any denotation scheme would suffice. This exposes lock pin 128 in the neck 124 of the bolt body, which is removed and allows the firing pin 140 to also be removed (FIG. 5B). It should be noted that any means of securement of lock pin 128 may be utilized, and in the illustrated case a ball detent is used. After the firing pin 140 is removed, selector pin 126 may also be removed (FIG. 5D). It should be noted that a hole in selector pin 126 accommodates firing pin 140, which secures selector pin 126 in place. Other means, like a ball detent may also be used. After the selector pin 126 is removed, the whole bolt body 120 may be removed and then inserted into the other side of carrier 110 (FIGS. 5E and 5F). The process is then reversed (FIGS. 5G-5I) with selector pin 126 now in right helical slot 114, denoted with an “R” or some other denotation.

In firing, FIGS. 10A-10F and 11A-11F, the bolt 10, including bolt body 120 and carrier 110 present a cartridge into battery position. To do this, the cartridge 140 is first grasped by the extractor 134 when the bolt 10 is in a reloading position (FIGS. 6-9), usually at the opposite end of the bolt stroke than battery. The extractor 134 is biased against spring pressure into an open position, allowing the cartridge 150 to be seated within a rim 123 in the bolt head (FIG. 9). This is usually accomplished by an interaction with the receiver. When the bolt 10 passes the ejection port, the spring pressure engages the extractor 134 about a rim of the cartridge. The bolt 10 then pushes the cartridge 150 into battery. When the bolt 10 and cartridge 150 are in battery position, the cartridge 150 and bolt body 120 may not move any further forward (10A, 11A), however, the carrier 110 continues forward (10B, 11B). This continued forward movement forces the selector pin 126 to act against the helical slot 112 in which it resides, causing a gradual twisting motion to be imparted on the bolt body 120 (10C, 11C). As the twisting continues, the extractor 134 moves into a 12:00 o'clock position (10E, 11E) and the firing pin 130 is released, causing an initial recoil of the bolt body 120 (10F, 11F) and sends the whole bolt 10 away from battery to begin the firing cycle again. As the bolt retracts, the extractor 134 maintains its hold on the cartridge 150 until it interfaces with the receiver or other structure again, thereby opening and releasing the cartridge 150 out the ejection port. The selection of direction shown in FIGS. 5A-5I changes the direction of the twist in relation to the firearm, allowing the eventual ejection to occur through either a right or left port.

INDUSTRIAL APPLICABILITY

The present invention has industrial applicability as it may be manufactured as a product of industry and is a component for a firearm. As such, it may be fashioned of any suitable material, with preference given to metals such as steel. The individual shape of the components may be driven by the eventual shape and geometry of the firearm in which the bolt is intended to be used. The bulbous nature of the bolt body may be increased or reduced, even to the point of no longer being bulbous per se, as necessary to secure ammunition and also pass through the mechanism of the firearm.

Although the present invention has been described with reference to preferred embodiments, numerous modifications and variations can be made and still the result will come within the scope of the invention. No limitation with respect to the specific embodiments disclosed herein is intended or should be inferred. 

What is claimed is:
 1. A firearm bolt comprising: a bolt carrier with two open sides; a bolt body insertable in either side of the bolt carrier, said bolt body further having a head to interface with a firearm cartridge; a firing pin residing within the bolt body, capable of extending through the head of the bolt body; wherein insertion of the bolt body selectively into either side of the bolt carrier facilitates selection of a direction of ejection of a spent firearm cartridge.
 2. The firearm bolt of claim 1, further comprising two opposed helical slots on a dorsal side of the bolt carrier and a selector pin selectively residing in a neck of the bolt body which will interface with one of the opposed helical slots and impart a twist on motion of the bolt body relative the bolt carrier.
 3. The firearm bolt of claim 2, the head of the bolt body having a bulbous nature and further comprising a plurality of lugs about a rim, at least one lug holding a retraction latch.
 4. The firearm bolt of claim 3, said retraction latch being spring-biased.
 5. The firearm bolt of claim 2, the bulbous nature of the bolt head preventing the bolt body from being able to pass through the bolt carrier.
 6. The firearm bolt of claim 2, the head of the bolt body further comprising a plurality of lugs about a rim, at least one lug holding a retraction latch.
 7. The firearm bolt of claim 6, said retraction latch being spring-biased.
 8. The firearm bolt of claim 2, the neck of the bolt body presenting at least two alternate holes in which the selector pin may be placed.
 9. The firearm bolt of claim 8, the head of the bolt body having a bulbous nature and further comprising a plurality of lugs about a rim, at least one lug holding a retraction latch.
 10. The firearm bolt of claim 9, said retraction latch being spring-biased.
 11. The firearm bolt of claim 8, the bulbous nature of the bolt head preventing the bolt body from being able to pass through the bolt carrier.
 12. The firearm bolt of claim 8, the head of the bolt body further comprising a plurality of lugs about a rim, at least one lug holding a retraction latch.
 13. The firearm bolt of claim 12, said retraction latch being spring-biased. 